Drafting system



Dec. 25, 1928. 1,696,553

H. A. OWEN DRAFTING SYSTEM Filed NOV. 26,( 1926 JNVENTOR.

/M /2 'M7 ATTORN s.

Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

HENRY A. OWEN, OF WHITINSV'ILLE, MASSACHUSETTS, ASSIGNOR T0 WHITIN MA- CHINE WORKS, OF WHITINSVILLE, MASSACHUSETTS, A CORPORATION OF MAS- SACHUSETTS.

Application le'd November The invention relates to draftin systems for cotton spinning and like mac ines, its object being to provide a simple roll combina-` tion which is as easy for the operator to thread up and keep in order as the common three-roll system now in general use and which is capable of use throughout a wider `range of draft ratios to produce yarn .of better break test, and more particularl one which permits the commercial use of rafts higher than 10. By this system, a s1 le drafting of 22 or higher produces yarn o a break test as good or better than obtained by equivalent elongation produced in several draftings. Heretofore such result has 'been obtained only at the expense of relatively complicated drafting apparatus mvolvlng the use of belts, friction plates and other oo ntrivances likely to et out of order and d1f- '20 fieult to keep in goo working condition. The

characteristic of the present invention is that a level yarn is produced within the so-called high-draft range, or a stronger yarn at any lower draft, by the use of rolls alone without 25 need of belts or inter-roll guiding means of any kind, the roll organization bein just as simple as that heretofore commo y used, practically as cheap to build in the first instance, and requiring no speciall skill or attention to maintain in permanent service.

The drawing illustrates the preferred form of the invention, Fig. 1 being di atie;

Fig. 2 a cross section of the rolls showingv the weightin system; and

Fig. 3a p an of Fig. 2.

The system comprises or includes a pair of front or delivery rolls 1 and 2, a group of intermediate rolls 3, 4 and 5, and a pair of back rolls' 6 and 7. The four lower rolls 2, 4, 5 and 7 are journalled in roll stands 8 as usual and are all positively driven, being formed on continuous shafts extending the length of the machine as usual and driven at the rates explained below, by gearing at the end of the machine. This gearing is not illustrated because it can'be readily supplied byany mechanic. The front top roll 1 andthe back top roll 6 are held in superposition on their respective lower rolls by the engagement .of their gudgeons in the slots ofthe back bar arms 9, as usual. ,These arms and also the roll stands are shown of conventional design and are provided with usual adjustment facilities, including an extensible back bar 'iin- DBAFTIN G SYSTEM.

26, 1926. Serial N0. 150,681.

ger 10. The top rolls 1 and 6 of the front and back pairs are `weighted by a saddle 11 and stirrup 12, or they might be self-weighted, the pressure in any event being sui'iicient to prevent any slipping of the roving and for the same purpose these rolls may be leather covered. In the present case the weighting system includes an arm 11a hinged to the back bar and arranged to bear on the rear top roll 6. The saddle 11 'rests by its rear end in a groove in the weighting arm 11, n occupying diii'erent positions therein 'according to the adjusted distance between rolls 1 and 6. The stirrup 12 bears on the saddle 11 through its adjustment screw 12a and always at the same point on the'saddle for all adjustments, so that the manipulation of the screw 12El has no eifect except to shift the position of the stirrup relatively to the saddle and the distribution of the weight, to the rolls 1 and 6 is always substantially in the same fixed ratio. The saddle 11 is highv enough `to `permit the roll 3 to be easily removed from under it when desired. The bottom srolls 2 and 7 are fluted rolls, and the two pairs of rolls 1-2, and 6 7, maybe termed non-slipping rolls as distinguished from the intermediate group which is arranged to permit the rovmg to slip, relatively, through them.

The top intermediate roll 3 is supported in and by the crotch of the two lower intermediate rolls 4 and 5 and driven by them, being free of all contact with the back bar arms 9, except such 'as may be necessary to guard against lits endwise displacement. It is thus free of frictional restraint or retardation, but it may have a clearer. The rovin which may be single or double as desire passes under the top roll and over the rolls 4 and 5, as indicated by dotted lines, and the 5 pathl wilebe seen to be straight enough to be self-threading, which is to say, that a broken end introduced straight into the backrolls will pass through the system coming out at the front rolls without requiring the lifting m0 of any rolls. ,v For convenience of reference the portion of the yarn path between the back and intermediate rolls is designated a; that portion of it which lies between the nip lines of rolls 4 and `5 is designated and that bel tween the nip line of roll 4 and the front rolls,

as c.

The top roll 33 is a gravity roll meaning thereby that it is not weighted by stirrupor other applied weight. Its own weight is distributed on two lines of roving as indicated by Fig. 3, one passing under it near each end, and it has two points of bearing on each, or four points of contact altogether. This is deemed important as thereby the roll 3 is rotated steadily and at the average speed of all the fibres passing beneath it, being helped along by other points of lContact whenever it would otherwise tend to lag at one of them. Whileit might be possible to use an applied weight on this roll, under conditions which would not involve objectionable interference with its free rotation, such weighting is not desirable and is not in fact necessary. The weight of the roll itself can be sufficient for all purposes. 60s, it may properly weigh about 10 oz.; for heavier yarns, such as 10s or heavier, it can be 12 oz., and ordinarily one weight of roll is satisfactory for all the yarn sizes which a given frame will ever be called upon to produce.

The intermediate bottom roll 4 is relatively small, about 1/2 in diameter, and is journalled close to the front rolls and with its top surface in a position slightly higher than the plane which is common to the nip lines of front rolls 1 and 2 and intermediate rolls 3 and 5, and so that the roving portion c wraps around or bends over said roll for a portion of its circumference, approximating oneeighth of it or 45 of arc. Its proximity to the front rolls is such that the roving distance 0 is slightly less than the average length of the staple. The relatively sharp curvature of the roving in the section c is also deemed important inasmcuh as the forward ends of some of the fibres emerging from the rolls 3-4 thereby have an opportunity to spring up clear of their companions and straighten out by their own inherent stiffness before and as they are drawn together into the nip of the front rolls.

The intermediate lower roll 5 may be of l the same or larger diameter than its companion roll 4 so long as it is so placed that it forms a crotch in which the top intermediate roll 3 can be sustained without need of extraneous guidance. It is driven at the same surface speed as its companion roll. The distance b for which the yarn is in contact with the top intermediate roll 3 will be seen to be slightly variable according to the diameters.

of the rolls of the group, but variation of this distance, within such limits, is apparently without effect Von the product. In the case in hand, all the rolls, except roll 4, are of approximately the diameters standard in ringspinning frames; to be specific, the diameter of rolls 1 and 6 is inch, of 5 and 7 is '178 inch, and of rolls 2 and 3 is 1 inch. The roving distance a is set slightly greater than vthe staple length, say from 1% to 11/2 inches.

For fine yarns of the order ofmemes r1he roving distance c is set, as above stated, so that it is always slightly less than the staple length; the .roll 3 being set on the staple as it is termed. The adjustment of the distance c is ordinarily accomplished by changing the position of the extension finger 10 which holds the top front roll 1, and so as to shift that roll backwards or forwards as conditions require, but for staple longer than 11A inch it is desirable to change also the distance between centers of the bottom rolls 2 and 4-5, as by the use .of the adjustments provided in the roll-stand base.

`The intermediate rolls 3, 4 and 5 are slipping rolls, as above stated, which is to say, that they are intended to permit the staple to be drawn through them, slipping through both nip lines. The lower rolls 4 and 5 may be and preferably are smooth or at least not sharply luted, which would interfere with slipping. The top roll 3 is smooth, cast iron or leather-covered, and preferably the former.

The draft ratio figured on the surface speed of the rolls is preferably 1.5 for the distance a or between 1 and 2.25, and anywhere from, say, 6 to 35 for the combined distances a, b and c, an over-all draft ratio of 22 being generally preferred for so-called highdraft spinning. The actual draft in distance ais or may be greater than the ratio of the roll speeds above given because the staple pulls through the intermediate rolls under the draft of the higher speed non-slipping front rolls.

It is importantI that the top intermediate roll 3 be supported solely by the crotch of its two companion rolls, inasmuch as frictional retardation upon it, such as would occur if it had gudgeons rubbing against back bar slots, is thus avoided and any retardation is found to interfere with the production of level yarn. Such top roll may however be provided with gudgeons if desired so long as the latter do not normally subject the roll to objectionable retarding friction. The plane of the ni lines of the rolls 4 and 5 should thus be substantially horizontal so that the top roll will not be likely to become displaced in use and so that its weight will be about evenly distributed upon both rolls as above pointed out.

Within the principles above disclosed, it will be apparent that various modifications of the specific arrangement illustrated will produce equivalent results and without departing from this invention.

1. In a drafting roll system for roving, the combination of front and back pairs of rolls operating under pressure whereby they are non-slipping in relation to the roving, and a group of intermediate rolls two of which are positively-driven rolls and a third of which rests in the crotch of the other two being driven by them, one of said positivelydriven intermediate rolls being of relatively small diameter, as compared to said front and back rolls, and located close to said front rolls whereby its nip line is spaced less than the staple length from the nip line of said front rolls, the intermediate top roll being adapted to permit the roving to pull through beneath it under the draft exerted by said front rolls.

2. The combination of claim 1 wherein the said relatively small intermediate roll is so situated that approximately one-eighth or more'of its circumference has contact with the roving passing to the front rolls.

3. The combination of claim 1 wherein the two lower intermediate rolls have their respective nip lines in a substantially horizontal plane thereby producing substantially` roving thereby having four points of contact whereby it is driven.

5. The combination of claim 1 in which the top front roll is adjustable around the circumference of the top lower roll in adjustment to different staple lengths.

6. The combination of claim 1 in which the speed ratio between the back and intermediate rolls approximates 1.5.

In testimony whereof, 'I have signed this specification.

- HENRY A. OWEN. 

